Homemade Ball Mill
OK...so you want to make fireworks. The first and most important thing you'll need is black powder. I couldn't buy it locally, and why bother when I could make my own. In order to obtain a good quality powder, you'll need a ball mill (among other things). I designed mine based on Dan Williams' information and it worked great.
The heart of the mill is the motor. I used a ½ hp 1725rpm 115v motor that I found on e-bay. There is usually a wide selection there with decent prices. Mine was reconditioned, but runs great and the seller even put a power cord on it for me. The drive shaft is ½ inch diameter to which I attatched a 2 inch O.D. sheave. The larger sheave is 6 inch O.D. and attaches to a length of 5/8 inch steel rod, and the two are connected by a standard V belt. The steel rod is supported by a pair of 5/8 inch self centering pillow block bearings. I had to file down the ends of the rod a bit to allow it to fit in the openings of the bearings. The support roller I used was simply an equipment roller which I purchased from a wood working site. It's 2 inches in diameter and covered with a bicycle innertube for friction. To accomplish this, a 26 x 2 inch innertube is cut near the valve, tied off tightly on both ends, and inflated. The roller is then pushed into an end until it's fully enclosed. The ends are cut off to allow it to deflate, then trimmed.
The drive rod has a section of 5/8 inch heater hose slipped onto it for friction. I built the frame out of a piece of shelving I had, mounted on a support frame of 2x4's. You could add some sort of bumpers to keep the mill jar contained, but mine ran true enough that the jar didn't noticably creep even after 5 hours of continuous running.
The last component is the milling jar itself. This is a picture of one of mine, but unfortuneately I don't have construction pictures to go with it. There are many possibilities for jars, the ones I constructed are detailed on Dan's Page.
This mill worked very well for my original needs and could produce a batch of good quality meal powder in 3-4 hours. If you're interested in building your own mill and have any questions, don't hesitate to e-mail me.
Here are some pictures of my improved mill. If you're interested in building one similar, I highly recommend joining Passfire.